Correction

GEOLOGY. For the article “Atomic force microscopy of Precambrian microscopic fossils,” by André Kempe, J. William Schopf, Wladyslaw Altermann, Anatoliy B. Kudryavtsev, and Wolfgang M. Heckl, which appeared in issue 14, July 9, 2002, of Proc. Natl. Acad. Sci. USA (99, 9117–9120; first published June 27, 2002; 10.1073/pnas.142310299), the authors note that the adhesion forces measured over the cell wall of the fossil acritarch are ranging up to 90 nN instead of 90 pN throughout the text and figures.